The present invention relates generally to location awareness in wireless networks and more particularly to power management in wireless devices connected via a direct link.
Various wireless standards, such as Institute of Electrical and Electronics Engineers (IEEE) standards 802.11 a/b/c/e/g/i (referred to collectively as IEEE 802.11), provide for wireless connectivity between a wireless station and an infrastructure network (e.g., the Internet) via an access point. Processes covered by these standards include the association of a wireless station with an access point, the transmission of data from wireless station to infrastructure network, and vice versa, via the access point, communication between wireless stations via an access point, and the like.
Some wireless standards, such as the direct link protocol (DLP) proposed for inclusion in IEEE 802.11e, provide a technique for initiating direct communications between wireless stations without the access point acting as an intermediary for the forwarding the data frames. The direct communications are commonly referred to as a wireless “direct link.” These conventional direct link processes, however, require active cooperation from the access point in initiating and establishing the direct link. It will be appreciated that the access point may be configured to prevent the establishment of a direct link or may be incapable of supporting direct link capabilities (e.g., modulation type) preferred by the wireless stations. Wireless stations using conventional direct link techniques therefore may be unable to establish a direct link or may restricted to establishing and using a direct link with capabilities limited to the supported capabilities of the access point. Moreover, these conventional direct link specifications (IEEE 802.11e DLP and IDLP) fail to provide an adequate technique to allow peer stations to enter a sleep state during the existence of a direct link connecting the peers. Thus, both peers remain in the awake state during the direct link and needlessly drain power from their power supplies.
Accordingly, techniques for effective power management in wireless stations connected by direct links would be advantageous.